Infradian and ultradian rhythms evaluation Flashcards
What is the evolutionary basis of the menstrual cycle?
It is thought it may have been advantageous for our female ancestors to menstruate together and therefore fall pregnant around the same time meaning the new borns could be cared for collectively, increasing the chance of survival
Why has the validity of the evolutionary perspective been questioned?
Schank suggested that if there was too many females cycling together within a social group this would produce competition for the highest quality males so therefore the avoidance of synchrony would appear to be the most adaptive strategy
What are the methodological limitations in synchronisation studies?
It is argued there are many factors that could affect changes in a womans cycl e.g. stress, changes in diet, exercise etc that may act as confounding variable
Supporting patterns of synchronisation is expected to have occurred through chance
Some studies failed to fine evidence of menstrual synchrony in any sample
What was Dement and Kleitman’s research into the stages of sleep?
Monitored the sleep patterns of 9 participants in a lab (brainwave activity recorded on an EEG) and the researcher controlled for the effects of caffeine and alcohol
REM activity during sleep was highly correlated with the experience of dreaming and brain wave activity varied according to how vivid the dreams were
Replications reported similar findings but small sample criticised by some
But suggests our REM is important component of the ultradian sleep cycle
What is the evidence from animals studies?
Much of the knowledge of the effects of pheromones on behaviour is derived from animal studies e.g. the fact that sea urchins release pheromones into the surrounding water so that Asians in the colony will adjust their sex cells simultaneously
However evidence foe the effects on human behaviour remain inconclusive
What is a practical application?
One of the most effective treatments for SAD is phototherapy - this is a light box that simulates very strong light in the morning and evening and its thought to reset melatonin levels - this relives symptoms in up to 60% of sufferers
Why are some people sceptical about phototherapy?
The same study reported a placebo effect of 30% using a sham negative ion generator which casts doubt on the chemical influence of phototherapy
